Papermaking involves the preparation of a paper product from an aqueous suspension of cellulosic fibers by forming a mat of interwoven fibers and removal of water from the mat by various dewatering methods including free drainage, vacuum, pressing, and evaporative drying. A problem that is observed during the papermaking process and for the finished paper is the tendency for paper to release fiber and filler particles from the paper surface, leading to the formation of lint and dust. Excessive dusting can pose problems during the manufacture of tissue products, and can result in runnability and quality issues on papermaking machines. Moreover, dust and lint accumulation can create a fire hazard. In papermaking, there is also the potential for workers to be exposed to paper dust. Regular exposure to high levels of dust can affect the respiratory system and cause illness.
Tissue paper is a lightweight paper that can be used to prepare absorbent products such as bath tissue, facial tissue, and absorbent towels. Tissue paper is generally prepared by forming a wet web of wood pulp and transferring the web to a heated cylinder called a Yankee dryer to reduce the moisture content. The tissue paper is subjected to a creping process where the paper is scraped off of the Yankee Dryer by contacting a blade against the dryer. Creping makes the tissue sheets flexible, soft, and absorbent. Ideally, the resulting tissue should have high softness, while also having sufficient strength and resistance to dusting.
The creping process typically suffers from dusting issues, which occurs during contact of the creping blade with the tissue sheet. Loose dust particles are generated when mechanical force is applied to tissue paper, and is more pronounced in processes where tissue sheets are weak or loosely bonded. As generally observed in papermaking processes, the surface and fine fibers of the tissue are dispersed into air and settles on papermaking equipment. High dusting and linting tissue can create a nuisance for consumers with regard to cleanliness of the tissue/towel dispenser and surrounding areas.
A number of methods are used to reduce linting and dusting. Air jets as well as vacuum systems positioned near the papermaking process have been used to remove lint and dust released from the paper substrate, but these methods are generally energy inefficient and do not address dust generated by handling of the finished paper products.
Tissue dusting and linting remain a significant problem in the field and there continues to be a need for new strategies for dust reduction in tissue making.